1. Field of the Invention
This invention relates to a connector having a structure for preventing a liquid such as water and oil form intruding into a terminal receiving chamber in a connector housing.
2. Related Art
There is known one conventional connector with a liquid intrusion prevention structure (which has been marketed by YAZAKI Parts Co., Ltd.), in which a silicone filler is filled in each male terminal receiving chamber which is formed in a connector housing, and receives a male tab terminal (male terminal). This connector is shown in FIGS. 9, 10 and 11. As shown in FIGS. 9, 10 and 11, the connector 50 (which is a male connector) includes the male connector housing 51 having the male terminal receiving chambers 52 formed therein.
Each male tab terminal 53, electrically connected at its wire connection portion 71 to a wire 70, is received in the corresponding male terminal receiving chamber 52 such that its electrical contact portion 72 projects outwardly from the male connector housing 51. The silicone filler 54 is filled in the male terminal receiving chamber 52, and a waterproof rubber plug 55 of an annular shape is inserted between an opening peripheral surface of the male connector housing 51 (which defines a rear opening (with respect to a connector fitting direction) of the male terminal receiving chamber 52) and the wire 70, thereby sealing the male terminal receiving chamber 52.
Therefore, the silicone filler 54 prevents a liquid, such as water and oil, from intruding into the male connector housing 51 from that side where the electrical contact portion 72 of the male tab terminal 53 is disposed, and also the waterproof rubber plug 55 also prevents a liquid, such as water and oil, from intruding into the male connector housing 51 from that side where the wire 70 is disposed.
In the above connector 50, however, it is necessary to use a special-purpose machine for pouring the silicone filler 54 into the male terminal receiving chamber 52, and besides time and labor are required for operating this special-purpose machine, and therefore this is disadvantageous from the viewpoint of the cost.
Furthermore, generally, the silicone filler 54 has high viscosity, and therefore in order to ensure the smooth pouring, the connector must be so designed as to provide a relatively large gap within the male terminal receiving chamber 52. Therefore, when the amount of pouring of the silicone filler 54 into the male terminal receiving chamber 52 is small, the male tab terminal 53 is liable to considerably shake relative to the male connector housing 51. And besides, when the connector 50 is to be used in a vehicle such as an automobile, the silicone filler 54 must be effectively filled in a gap within the male terminal receiving chamber 52 so that the connector 50 can withstand vibrations.
Generally, the adhesion of the silicone filler 54 is liable to be broken by a so-called thermal shock due to an abrupt change in the ambient temperature, and various measures must be taken in order to maintain the initial liquid intrusion prevention performance of the connector 50 for a long period of time.
There is known another connector having a liquid intrusion prevention structure different from that of the above connector 50 (see, for example, JP-A-2003-109702 (FIGS. 1 to 3)). In the connector (an oil/water-proof terminal structure) disclosed in JP-A-2003-109702, a tubular elastic seal member (rubber packing) is mounted on a male tab terminal (metal terminal), and this elastic seal member is held in intimate contact with an inner surface of a male connector housing and the male tab terminal within a male terminal receiving chamber, thereby preventing a liquid, such as water and oil, from intruding into the male terminal receiving chamber from that side where an electrical contact portion of the male tab terminal is disposed. The connector, disclosed in JP-A-2003-109702, can perfectly eliminate the drawbacks encountered with the pouring of the silicone filler 54 in the connector 50.
However, the above elastic seal member is made 100 percent of rubber (usually, synthetic rubber), and in the liquid intrusion prevention structure in which the 100% rubber-made elastic seal member is merely clamped between the male connector housing and the male tab terminal, there is a high possibility that the shaking of the male tab terminal relative to the male connector housing occurs due to aged deterioration such as contraction of the rubber material forming the elastic seal member, so that the liquid intrusion prevention performance is lowered. In addition, when assembling the connector disclosed in JP-A-2003-109702, the male tab terminal, having the long tubular elastic seal member mounted thereon, must be pushed into the male connector housing, and therefore the assembling operation is difficult, and besides there is a possibility that the male tab terminal is bent by this pushing force.